Integrated conveyor motor

ABSTRACT

A conveyor assembly includes a conveyor module including first and second roller bodies and a conveyor belt; a chassis; and a tensioning system. The tensioning system is operable to adjust the tension of the conveyor belt and includes a tensioning device selectively shiftably mounted to the chassis such that shifting of the tensioning system in the fore-aft direction along the chassis results in corresponding fore-aft shifting of the first roller body relative to the second roller body, thereby facilitating adjustment of the tension of the conveyor belt. The chassis includes a pair of side rails and a slider bed. A stiffening assembly includes a bracket spaced vertically below the slider bed such that a vertical gap is formed between the slider bed and the bracket. The stiffening assembly further includes an insert disposed on the bracket and extending upward across at least a portion of the gap.

CROSS-REFERENCE TO RELATED APPLICATION 1. Priority Application

The present application is a continuation-in-part of U.S. patent application Ser. No. 16/892,959, filed Jun. 4, 2020, which claims the benefit of and priority from U.S. Provisional Patent Application No. 62/857,157, filed Jun. 4, 2019, the entire disclosure of each of which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to a motor-driven conveyor assembly.

2. Discussion of the Prior Art

Conveyor assemblies with motor-driven conveyor belts are often used in the materials handling industry for transport and/or distribution of goods in a workspace such as a commercial warehouse. Some known conveyor systems include a scrolling belt supported by a pair of rollers, with one of the rollers being rotatably powered by a motor via indirect attachment thereto (e.g., via a transmission such as a pulley drive).

However, conventional conveyor assemblies have various deficiencies. Among other things, for instance, conveyor assemblies with pulley drives conventionally use tensioning mechanisms that make the conveyor assemblies expensive to manufacture and maintain.

SUMMARY

According to one aspect of the present invention, a conveyor assembly for use with a mobile vehicle comprises a conveyor module, a power module, a vehicle chassis, and a tensioning system. The conveyor module includes a first roller assembly including a first roller body rotatable about a first axis, a second roller assembly spaced from the first roller assembly in a fore-aft direction and including second roller body rotatable about a second axis, and a conveyor belt shiftable in response to rotation of at least one of said first and second roller bodies. The power module provides rotational power to at least one of the first and second roller bodies. The chassis supports the conveyor module. The tensioning system is operable to adjust the tension of the conveyor belt. The tensioning system includes a tensioning device. The tensioning device is coupled to the first roller assembly and selectively shiftably mounted to the chassis such that shifting of the tensioning system in the fore-aft direction along the chassis results in corresponding fore-aft shifting of the first roller body relative to the second roller body, thereby facilitating adjustment of the tension of the conveyor belt.

Among other things, provision of a tensioning device coupled to the first roller assembly and selectively shiftably mounted to the vehicle chassis such that shifting of the tensioning system in the fore-aft direction along the chassis results in corresponding fore-aft shifting of the first roller body relative to the second roller body, thereby facilitating adjustment of the tension of the conveyor belt, enables efficient and secure adjustment, setting, and maintenance of the conveyor belt tension.

According to another aspect of the present invention, a conveyor assembly comprises a conveyor module, a chassis, and a stiffening assembly. The conveyor module include a first roller assembly including a first roller body rotatable about a first axis, a second roller assembly spaced from the first roller assembly in a fore-aft direction and including a second roller body rotatable about a second axis, and a conveyor belt shiftable in response to rotation of at least one of said first and second roller bodies. The chassis includes a pair of side rails each extending in the fore-aft direction and a slider bed extending between and interconnecting the side rails. The slider bed underlies a portion of the conveyor belt. The stiffening assembly includes a bracket extending between and interconnecting the side rails. The bracket is spaced vertically below the slider bed such that a vertical gap is formed between the slider bed and the bracket. The stiffening assembly further includes an insert disposed on the bracket and extending upward across at least a portion of the gap.

Among other things, provision of a stiffening assembly including a bracket extending between and interconnecting the side rails, wherein the bracket is spaced vertically below the slider bed such that a vertical gap is formed between the slider bed and the bracket, and wherein the stiffening assembly further includes an insert disposed on the bracket and extending upward across at least a portion of the gap, facilitates effective and low-cost stiffening of the chassis and reductions in operational noise.

This summary is provided to introduce a selection of concepts in a simplified form. These concepts are further described below in the detailed description of the preferred embodiments. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Various other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Preferred embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 is a rear side perspective view of a mobile conveyor system in accordance with a first preferred embodiment of the present invention, wherein the mobile conveyor system includes a conveyor assembly and a vehicle supporting the conveyor assembly;

FIG. 2 is an alternate rear side perspective view of the mobile conveyor system of FIG. 1;

FIG. 3 is a side view of the conveyor assembly of FIGS. 1 and 2;

FIG. 4 is rear elevational view of the conveyor assembly of FIG. 3, taken along line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view of the conveyor assembly of FIGS. 3 and 4, taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged, partially sectioned view of the conveyor assembly of FIGS. 3-5, particularly illustrating a portion of the drive roller, the power module, and motor mounting structure formed by the chassis;

FIG. 7 is a further enlarged view of a portion of the conveyor assembly as shown in FIG. 6;

FIG. 8 is a perspective view of drive roller bearing adapter or insert;

FIG. 9 is a cross-sectional view of the drive roller bearing adapter or insert of FIG. 8;

FIG. 10 is a front perspective view of a mobile conveyor system in accordance with a second preferred embodiment of the present invention, wherein the mobile conveyor system is shown in a package distribution environment and includes a conveyor assembly and a vehicle supporting the conveyor assembly;

FIG. 11 is a rear perspective view of the conveyor assembly of FIG. 1;

FIG. 12 is a side view of the conveyor assembly of FIGS. 10 and 11;

FIG. 13 is a cross-sectional rear view, taken along line 13-13 of FIG. 12, of the conveyor assembly of FIGS. 10-12, particularly illustrating the stiffening assembly;

FIG. 14 is a cross-sectional side view, taken along line 14-14 of FIG. 13, of the conveyor assembly of FIGS. 10-13, further illustrating the stiffening assembly;

FIG. 15 is a bottom perspective view of the conveyor assembly of FIGS. 10-14, with the conveyor belt removed;

FIG. 16 is an enlarged, partially exploded rear perspective view of a portion of the conveyor assembly of FIGS. 10-15, particularly illustrating the tensioning system;

FIG. 17 is a top, rear perspective view of the chassis of the stiffening assembly of the conveyor assembly of FIGS. 10-16;

FIG. 18 is a bottom, rear perspective view of the chassis of FIG. 17;

FIG. 19 is an enlarged, partially sectioned front perspective view of a portion of the conveyor assembly of FIGS. 10-16, particularly illustrating the power module;

FIG. 20 is a further enlarged, partially sectioned front perspective view of a part of the portion of the conveyor assembly shown in FIG. 19, further illustrating the power module; and

FIG. 21 is an alternative front perspective view of the part of the portion of the conveyor assembly shown in FIG. 10, also particularly illustrating the power module.

The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. While the drawings do not necessarily provide exact dimensions or tolerances for the illustrated structures or components, the drawings are to scale with respect to the relationships between the components of the structures illustrated in the drawings.

DETAILED DESCRIPTION

The present invention is susceptible of embodiment in many different forms. While the drawings illustrate, and the specification describes, certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments.

Furthermore, unless specified or made clear, the directional references made herein with regard to the present invention and/or associated components (e.g., top, bottom, upper, lower, inner, outer, etc.) are used solely for the sake of convenience and should be understood only in relation to each other. For instance, a component might in practice be oriented such that faces referred to as “top” and “bottom” are sideways, angled, inverted, etc. relative to the chosen frame of reference.

Conveyor System—First Embodiment

With initial reference to FIGS. 1 and 2, a mobile conveyor system 10 is provided. The mobile conveyor system 10 preferably comprises a conveyor assembly 12 and a vehicle 14 (shown schematically in hidden line). The conveyor assembly 12 is preferably mounted on and supported by the vehicle 14 in any manner providing suitable stability. More particularly, the conveyor assembly 12 preferably is fixed to a top surface 14 a of the vehicle 14.

The vehicle 14 is preferably moveable to facilitate positioning/repositioning of the conveyor system 10 as a whole and, consequently, of the conveyor assembly 12. In the illustrated embodiment, for instance, the vehicle 14 includes a plurality of wheels 15.

Most preferably, the vehicle 14 is powered, such that selective movement of the vehicle 14 may be accomplished through use of one or more vehicle motors (not shown) or other power sources. In a preferred embodiment, for instance, each of the wheels 15 is a drive wheel powered by a respective motor.

Movement of the vehicle 14 is most preferably automated, with the vehicle 14 being an autonomous guided vehicle (AGV) or robot. Detailed descriptions of suitable embodiments of the vehicle 14 may be found in U.S. patent application Ser. No. 14/960,138, U.S. patent application Ser. No. 15/047,244, U.S. Patent application No. 15,331,560, and U.S. patent application Ser. No. 15/433,923, each of which is incorporated in its entirety by reference herein.

Although a vehicle of the type described above is preferred, it is noted that movement may be controlled in any one or more of a variety of manners without departing from the scope of the present invention. For instance, vehicle movement might be controlled through an onboard user interface, be controlled remotely, or be manually controlled.

Still further, movement of the vehicle may be facilitated in a manner other than or in addition to wheeled rolling. For instance, the vehicle might additionally or alternatively be slidable, tracked, etc.

It is also permissible according to some aspects of the present invention for the conveyor assembly to be intended for stationary placement or have a limited range of motion. In such an instance, the vehicle might be omitted and replaced with a framework or other supporting structure fulfilling the particular positioning needs of the given application.

In a preferred embodiment, the conveyor assembly 12 broadly includes a conveyor module 16, a chassis 18, and a power module 20. As will be discussed in greater detail below, the conveyor assembly 12 is configured to facilitate the advancement of one or more items (not shown) supported thereon.

Conveyor Module

The conveyor module 16 preferably includes a conveyor belt 22, a drive or powered roller 24, and a driven or following/passive roller 26. The conveyor belt 22 preferably extends in fore and aft directions along a fore-aft or longitudinal axis of the conveyor module 16. The drive roller 24 and the driven roller 26 preferably extend parallel to one another and orthogonal to the longitudinal axis, in lateral or side-to-side directions. The rollers 24 and 26 are furthermore spaced from one another in the fore and aft direction (i.e., along the longitudinal axis).

The conveyor belt 22 preferably extends along the longitudinal or fore-aft axis to form a single, continuous (i.e., endless) loop around the rollers 24 and 26. More particularly, the conveyor belt 22 presents discrete lateral sides 28 and 30 but has no fore or aft edges. As will be discussed in greater detail below, rotation of the rollers 24 and 26 results in corresponding circulation of the conveyor belt 22 such that a given portion of the conveyor belt 22 presents an upper belt surface 22 a thereof at one moment but later, upon sufficient rotation of the rollers 24 and 26, presents a lower belt surface 22 b the conveyor belt 22. Furthermore, at any given moment, the conveyor belt 22 presents an upper run 23 a extending between and above the rollers 24 and 26, as well as a lower run 23 b extending between and below the rollers 24 and 26.

Most preferably, the conveyor belt 22 is entirely continuous, although it is permissible according to some aspects of the present invention for one or more discontinuities such as slots or openings to be formed therein. However, at least some degree of longitudinal continuity is most preferable to ensure efficient scrolling operability as described above.

It is also noted that it is permissible according to some aspects of the present invention for the belt itself to include a plurality of mini-belts, roller segments, or other components that collectively or collaboratively present an item-supporting surface and function in a scrolling manner as noted above. Furthermore, the conveyor assembly or conveyor module described herein might be sub-components of a larger system.

The items supported by the conveyor belt 22 (i.e., disposed on the upper belt surface 22 a thereof) may be of any one or more of a variety of types. For instance, one or more of the items might be a package or container such as a box, envelope, mailer, tube, carton, bag, tub, tote, can, drum, or crate. One or more of the items might instead or additionally be an unpackaged good or a bulk material (e.g., a particulate matter, etc.)

Chassis

The chassis 18 preferably comprises a pair of laterally spaced apart first and second side rails 32 and 34 disposed adjacent respective ones of the sides 28 and 30 of the conveyor belt 22. The first and second side rails 32 and 34 each preferably broadly extend both along and orthogonally to the longitudinal axis so as to be parallel to each other. Skewed rails or portions of the rails are permissible according to some aspects of the present invention, however.

The chassis 18 and, more particularly, the side rails 32 and 34, preferably rest on the vehicle 14 in such a manner as to elevate the conveyor belt 22 relative to the vehicle 14. That is, a gap 36 is formed between the vehicle 14 and the bottom surface 22 b or lower run 23 b of the conveyor belt 22.

The first and second side rails 32 and 34 are structurally similar in many regards but diverge with regard to structure associated with the aforementioned power module 20. For clarity, the first side rail 32 will therefore be referred to herein as the drive side rail 32. In contrast, the second side rail 34 will continue to be referred to herein simply as the second side rail 34. Key distinctions between the side rails 32 and 34 will be discussed in greater detail below.

With regard to common features, however, each of the side rails 32 and 34 includes a respective sidewall 38 or 40 extending upwardly and downwardly relative to the conveyor belt 22 such than a exposed upper portion 38 a or 40 a extends upwardly relative to the upper belt surface 22 a or upper run 23 a, and a lower portion 38 b or 40 b extends downwardly relative to the lower belt surface 22 b or lower run 23 b.

The drive side rail 32 further preferably includes a flange 42 including upper, lower, fore, and aft sections 42 a, 42 b, 42 c, and 42 d. The second side rail 34 similarly preferably includes a flange 44 including upper, lower, fore, and aft sections 44 a, 44 b, 44 c, and 44 d. The flanges 24 and 44 each extend laterally outwardly from the corresponding one of the sidewalls 38 and 40. The lower sections 42 b and 44 b of the flanges 42 and 44, respectively, are preferably configured to directly abut (i.e., rest on) the vehicle 14, although other configurations fall within the scope of the present invention.

In a broad sense, the side rails 32 and 34 provide lateral guidance to the conveyor belt 22, offer structural support to the conveyor module 16, protect and support various components of the conveyor assembly 12, and to at least some extent protect personnel from inadvertent contact with components of the conveyor assembly 12.

In addition to the side rails 32 and 34, the chassis 18 further preferably includes a subframe 46 that extends between and interconnects the side rails 32 and 34. Still further, the chassis 18 preferably includes a slider bed 48 (see FIG. 4) extending between the side rails 32 and 34 and below at least a portion of the upper run 23 b of the conveyor belt 22 to support the upper run 23 b.

The drive or powered roller 24 preferably includes a tubular roller body 50 presenting lateral ends 50 a,50 b and a pair of bearing adapters or roller inserts 56 and 58 in part received within and secured to respective ones of the ends 50 a,50 b. As will be discussed in more details below, the roller insert 56 is a drive insert 56 and varies slightly in structure from the other insert 58.

The driven or following/passive roller 26 is preferably similarly constructed to the drive roller 24, including a tubular roller body (not shown) and a pair of bearing adapters or roller inserts 60 and 62 most preferably constructed similarly or identically to the insert 58. Alternative configurations fall within the scope of the present invention, however.

The drive roller 24 is preferably rotatably supported on the chassis 18 by a pair of roller-supporting bearings 64 and 66. Similarly, the driven roller 26 is preferably supported on the chassis 18 by a pair of roller-supporting bearings 68 and 70. More particularly, in a preferred embodiment, each of the bearings 64, 66, 68, and 70 is supported in a respective seat 64 a, 66 a, 68 a, 70 a formed by the chassis 18.

The drive insert 56 is shown in detail in FIGS. 8 and 9. As illustrated, the drive insert 56 preferably includes a circumferentially constricted inboard connector portion 72, a circumferentially enlarged intermediate or crown portion 74 outboard of the connector portion 72, and a bearing support portion 76 outboard of the crown portion 74 and circumferentially constricted relative thereto.

The connector portion 72 is preferably received within the corresponding end 52 of the roller body 50 such that the connector portion 72 and the roller body 50 rotate in unison.

The crown portion 74 preferably presents an inner shoulder 74 a that engages the end 52 of the roller body 50 and an outer shoulder 74 b that engages the roller-supporting bearing 64. The crown portion 74 further presents an upper face 74 c that engages and guides the conveyor belt 22. Tapered faces 74 d and 74 e preferably extend from each lateral edge of the upper face 74 c.

The roller-supporting bearing 64 is preferably disposed on the bearing support portion 76. More particularly, the roller-supporting bearing 64 preferably encircles the bearing support portion 76.

The drive insert 56 preferably further includes a pulley support portion 78 outboard of the bearing support portion 76. A slot 78 a and a circumferential notch or groove 78 b are preferably formed in the pulley support portion 78. The pulley support portion 78 will be discussed in greater detail below.

In a preferred embodiment, the inserts 58, 60, and 62 are identical to or very nearly identical to the drive insert 56 except in that they are devoid of a pulley support portion. However, it is permissible according to some aspects of the present invention for fully identical or more divergent inserts to be provided.

Power Module

The power module 20 preferably includes a power assembly in the form of a motor assembly 80. The power module 20 further preferably includes a drive in the form of a pulley drive 82. The pulley drive 82 is operable to transmit driving power from the motor assembly 80 to the drive insert 56, rotating the drive roller 24 and advancing the conveyor belt 22.

In a preferred embodiment, the motor assembly 80 includes a motor 84, a housing 86, and a bearing assembly 88. The motor 84 is preferably an electric motor, although other motor types fall within the scope of the present invention. Non-motor power sources (for instance, batteries) might additionally or alternatively be provided without departing from the scope of some aspects of the present invention.

Most preferably, the motor 84 includes a stator 90 and a rotor 92. The rotor 92 is rotatable about a motor axis. The motor axis preferably extends laterally (i.e. perpendicularly to the longitudinal axis), although other axis orientations fall within the scope of certain aspects of the present invention.

The stator 90 preferably at least substantially circumscribes the rotor 92, such that the motor 84 is an inner rotor motor. Outer rotor motors or dual rotor motors fall within the scope of some aspects of the present invention, however.

The stator 90 preferably includes a stator core 94 and a plurality of electrically conductive coils 96 wound about the stator core 94.

Preferably, the rotor 92 includes a rotor core 98, a plurality of magnets 100, and a rotatable output shaft 102 (which may also be referred to as a motor or rotor shaft 102). The output shaft 102 preferably extends laterally outwardly beyond the rotor core 98 and the stator 90 for purposes to be discussed in greater detail below. It is noted that a variety of additional rotor configurations, including but not limited to spoked rotor configurations, fall within the scope of the present invention.

The motor housing 86 preferably in part defines a motor chamber 104 in which the motor 84 is at least substantially disposed. That is, in a preferred embodiment, the housing 86 at least substantially encloses the motor 84. In the illustrated embodiment, for instance, the housing 86 includes a cylindrical shell 106 and an inner end wall 108. The shell 106 preferably circumscribes the stator 90, the rotor core 98, the magnets 100, and a portion of the output shaft 102. The inner end wall 108 is preferably secured by any means known in the art (e.g., welding, adhesives, latches, threaded fasteners, bolts, and/or integral formation) to an inner end of the shell 10, such that the housing 86 is closed at an inboard end thereof

Mounting and Support of Motor

The motor 84 is preferably integrally mounted to the chassis 18, with the drive side rail 32 of the chassis 18 forming part of the housing 86. More particularly, the drive side rail 32 defines an outer endshield 110 that is preferably integrally formed by the sidewall 38. The outer endshield 110 preferably includes a disc-shaped, vertically oriented end wall 112, a circumferentially extending outer mounting lip 114, and a bearing support structure 116. The shell 106 of the housing 86 preferably circumscribes and abuts the mounting lip 114.

Preferably, the shell 106 and, more broadly, the motor assembly 80 is removably mountable to the drive side rail 32. More particularly, the motor assembly 80 is preferably removably mounted to the outer endshield 110 formed by the drive side rail 32. For instance, the mounting lip 114 preferably fits securely (e.g., via a friction fit or close slip fit) into the shell 106 such that the shell 106 and, in turn, the inner end wall 108, are supported thereon. Furthermore, it is permissible for the shell to be secured to the lip and/or the end wall via removable fasteners (such as screws or bolts), latches, or other shiftable or reconfigurable means.

However, permanent or semi-permanent connection means, including but not limited to welding, adhesives, extremely tight fits (such as friction fits or thermal fits), and integral formation fall within the scope of some aspects of the present invention. It is also permissible according to some aspects of the present invention for the shell to instead be integrally formed with the chassis or, more particularly, the sidewall of the drive side rail.

Provision of an integrated outer endshield 110 formed by the chassis 18 as described above eliminates the need for a separate endshield component, resulting in advantageous reductions in cost, complexity, and weight. Various of the features described above, including but not limited to the mounting lip 114, also facilitate reduced usage of fasteners, resulting in advantageous reductions in cost, complexity, and weight. It is noted that, although weight reduction is often deemed advantageous in motor system design, reduced weight is particularly desirable in the present invention due to mounting of the conveyor assembly 12 on the vehicle 14. That is, reducing the load that must be supported by the vehicle 14 is highly preferred.

It is also permissible according to some aspects of the present invention for the motor assembly to be devoid of the shell and/or the inner endshield. In such an embodiment, the stator might be secured directly to the chassis via threaded fasteners extending axially through the stator core and into engagement with corresponding threaded openings in the chassis. Such openings might be formed in an integral receiving pad or other suitable region of the chassis, or instead in a discrete component mounted to the chassis.

In a preferred embodiment, the bearing support structure 116 comprises a cylindrical or tube-like main body 118 and a disc-like end 120 defining a shaft aperture 122. The main body 118, the aperture 122, and the motor shaft 102 are preferably coaxial, such that the motor shaft 102 extends centrally through the aperture 122 and into a bearing pocket 124 defined internally by the main body 118 and the end 120.

The aforementioned motor bearing assembly 88 preferably includes inner and outer motor bearings 126 and 128 disposed in the bearing pocket 124 and supported by the main body 118 of the bearing support structure 116. The motor bearings 126 and 128 in turn preferably rotatably support the rotor shaft 102 and, more broadly, the motor 84 relative to the outer endshield 110 and drive side rail 32. Thus, in a preferred embodiment, the motor 84 is supported directly on the chassis 18 in a simple, efficient, removable, and lightweight manner.

It is noted that the bearing 126 and 128 preferably support the shaft 102 and, in turn, the motor 84 in a cantilevered manner. However, it is permissible according to some aspects of the present invention for the bearings to be alternatively positioned (e.g., on opposite axial ends of the rotor or shaft).

In a preferred embodiment, appropriate lateral positioning of the motor bearings 126 and 128 is effected by a spacer sleeve 130 disposed between the motor bearings 126 and 128, a retaining ring 132 secured in a groove 134 in the main body 118 adjacent the outer bearing 128, and a wavy washer 136 disposed between the inner bearing 126 and the end 120. An additional spacer sleeve 138 is disposed outboard of the outer bearing 128 to facilitate positioning of the outer bearing 128 relative to the pulley drive 82.

The motor bearings 126 and 128 are each preferably unit bearings. That is, the components of the motor bearings 126 and 128 are preferably pre-packed and fully enclosed. Such a configuration is advantageous in, among other things, preventing contaminant ingress. Other types of bearings are permissible according to some aspects of the present invention, however.

Pulley Configuration and Positioning

As noted previously, the pulley drive 82 is preferably operable to transmit rotational power from the rotor 92 to the drive insert 56 and drive or powered roller 24, resulting in fore or aft travel of the conveyor belt 22. As will be discussed in greater detail below, the pulley drive 82 preferably broadly includes a drive or powered pulley 140, a driven or passive/following pulley 142, and an endless or continuously extending drive belt 144.

More particularly, the drive or powered pulley 140 is preferably mounted to an outermost end 102 a of the motor shaft 102 and spaced outwardly from the outer bearing 128 by means of the spacer sleeve 138.

Preferably, the drive pulley 140 is secured to rotate with the motor shaft 102 by means of a key 146 received in corresponding shaft and pulley slots 148 and 150, respectively. That is, the key 146 preferably ensures that rotation of the output shaft 102 corresponds directly to rotation of the drive pulley 140. However, other interconnection means facilitating cooperative rotation of the motor shaft and the drive pulley may additionally or alternatively be used.

The driven or passive/following pulley 142 is preferably disposed above and at least in part in lateral alignment with the drive or powered pulley 140. That is, the drive pulley 140 and the driven pulley 142 are at least in part coplanar in a vertical and fore-aft plane. Most preferably, such plane extends parallel to the longitudinal axis.

The driven pulley 142 is preferably mounted to the pulley support portion 78 of the drive insert 156. Most preferably, the driven pulley 142 is secured to rotate with the driven insert 156.

The drive belt 144 preferably extends in a loop about both of the pulleys 140 and 142 and is also at least in part co-planar therewith.

It is noted that correct positioning of the drive belt and pulleys 140 and 142 via coplanarity, appropriate pulley spacing, etc. is essential to efficient operation of the pulley drive 82. As will be discussed in greater detail below, the present invention advantageously facilitates correct positioning of these components.

For instance, outward lateral shifting of the drive or powered pulley 140 (along with attached structures including the motor 84) is restricted primarily via engagement of the outer motor bearing 128 against the retaining ring 132 and engagement of the drive pulley 140 against a retaining ring 152 disposed about the motor shaft 102. Laterally inward shifting of the drive pulley 140 is restricted primarily via engagement of the of the inner motor bearing 126 relative to the end 120 of the bearing support structure 116, as modulated by the wavy washer 136. The spacer sleeves 130 and 138 also play a role in positioning of the drive pulley 140.

Outward lateral shifting of the driven or passive/following pulley 142 is restricted primarily via engagement of the driven pulley 142 against a retaining ring 154 disposed about the insert 56 so as to received in the notch or groove 78 b, and engagement of the bearing 64 against an inner side of a shoulder 156 of the sidewall 40 of the chassis side rail 32 (see FIG. 5). Laterally inward shifting of the driven pulley 142 is restricted primarily by engagement of the driven pulley 142 with an outer side of the shoulder 156 of the sidewall 40. Additional spacing control is preferably provided by a spacer 158 disposed between the driven pulley 142 and the bearing 64.

Appropriate vertical and fore-aft positioning of the drive pulley 140 is facilitated primarily by secure fitment of the motor bearings 126 and 128 within the main body 118 of the bearing support structure 116.

Appropriate vertical and fore-aft positioning of the driven pulley 142 is facilitated primarily by the positioning of the roller bearing 64 in the bearing seat 64 a.

Thus, the chassis 18, the motor bearings 126 and 128, the roller bearing 64, and other components cooperate to precisely locate the drive pulley 140 and the driven pulley 142 relative to one another. Such carefully controlled positioning enables the conveyor assembly 12 and, more specifically, the pulley drive 82 thereof, to be efficiently operable without the use of a tensioning device such as an idler pulley.

Although the illustrated pulley drive configuration is preferred, it is noted that is it permissible according to some aspects of the present invention for a tensioning device (including but not limited to an idler pulley) to be provided. Furthermore, an alternative or additional device or mechanism might be provided (i.e., in lieu of or in addition to the previously described pulley drive) to transmit power from the electric motor to the drive roller. For instance, a chain and sprocket drive might be utilized

Further still, although it is preferred that the motor shaft 102 directly drive the drive pulley 140, as illustrated, it is permissible according to some aspects of the present invention for the motor to be configured or mounted in such a manner as to require an intermediate transmission to transfer power from the output shaft to the drive pulley.

Conveyor System—Second Embodiment

A second preferred conveyor system is illustrated in FIG. 10. It is initially noted that, with certain exceptions to be discussed in detail below, many of the elements of the conveyor system 210 of the second embodiment are the same as or very similar to those described in detail above in relation to the conveyor system 10 of the first embodiment. Therefore, for the sake of brevity and clarity, redundant descriptions and numbering will be generally avoided here. Unless otherwise specified, the detailed descriptions of the elements presented above with respect to the first embodiment should therefore be understood to apply at least generally to the second embodiment, as well.

Similarly to the conveyor system 10, the conveyor system 210 of the second preferred embodiment preferably comprises a conveyor assembly 212 and a vehicle 214 (shown schematically in hidden line).

The vehicle 214 is preferably moveable to facilitate positioning/repositioning of the conveyor system 210 as a whole and, consequently, of the conveyor assembly 212. In the illustrated embodiment, for instance, the vehicle 214 has positioned the conveyor assembly 212 adjacent a chute 216 in a package distribution center 218 to enable transfer of a package 220 from the conveyor assembly 212 to the chute 216.

As discussed above with regard to the first preferred embodiment, movement of the vehicle 214 is most preferably automated, with the vehicle 214 being an autonomous guided vehicle (AGV) or robot. However, as also discussed above, the vehicle might in alternate embodiments be differently configured or omitted entirely.

In a preferred embodiment, the conveyor assembly 212 broadly includes a conveyor module 222, a chassis 224, a power module 226, a stiffening assembly 228, and a tensioning system 230.

Conveyor Module

The conveyor module 222 preferably includes a conveyor belt 232, a drive or powered roller assembly 234, and a driven or following/passive roller assembly 236. The roller assemblies 234 and 236 are preferably spaced from one another in a fore-aft direction or, alternatively stated, along a longitudinal/fore-aft axis of the conveyor module 222. The conveyor belt 232 preferably extends along the longitudinal or fore-aft axis to form a single, continuous (i.e., endless) loop around the roller assemblies 234 and 236.

The drive or powered roller assembly 234 includes a drive or powered roller body 238 rotatable about a first or drive roller axis. The driven or following/passive roller assembly 236 includes a driven or following/passive roller body 240 rotatable about a second or passive roller axis. Rotation of the roller bodies 238 and 240 results in corresponding shifting and circulation of the conveyor belt 232 such that a given portion of the conveyor belt 232 presents an upper belt surface 232 a thereof at one moment but later, upon sufficient rotation of the roller bodies 238 and 240, presents a lower belt surface 232 b of the conveyor belt 232. Furthermore, at any given moment, the conveyor belt 232 presents an upper run 233 a extending between and above the roller assemblies 234 and 236, as well as a lower run 233 b extending between and below the roller assemblies 234 and 236.

The tensioning system 230, in cooperation with the chassis 224, facilitates the application, adjustment, setting, and maintenance of appropriate tension of the conveyor belt 232 via the setting and maintenance of appropriate longitudinal spacing between the drive and passive roller assemblies 234 and 236, respectively. The tensioning system 230 and the chassis 224 will each be discussed in greater detail below.

The drive roller body 238 is preferably tubular or cylindrical in form and presents lateral ends 238 a and 238 b. The drive roller assembly 234 further preferably includes a pair of bearing adapters or roller inserts 242 and 244 in part received within and secured to respective ones of the ends 238 a and 238 b. A intermediate insert 246 is also provided in an intermediate position between the ends 238 a and 238 b.

The passive roller body 240 is also preferably tubular or cylindrical in form and presents lateral ends 240 a and 240 b. The passive roller assembly 236 further preferably includes a pair of bearing adapters or roller inserts 248 and 250 in part received within and secured to respective ones of the ends 240 a and 240 b.

Chassis

The chassis 224 preferably comprises a pair of laterally spaced apart drive and second side rails 252 and 254. The side rails 252 and 254 each preferably extend in the fore-aft direction and parallel to each other to present respective fore and aft ends 252 a,b and 254 a,b.

In contrast to those of the first preferred embodiment, the side rails 252 and 254 of the conveyor module 222 each preferably include a respective sidewall 256 or 258 disposed at least substantially laterally outward of the conveyor belt 232 and vertically between the upper and lower runs 233 a and 233 b, respectively, thereof. Extension of either or both of the sidewalls upward of the upper run and downward of the lower run is permissible without departing from the scope of some aspects of the present invention, however.

In addition to the side rails 252 and 254, the chassis 224 further preferably includes a slider bed 260 extending between and interconnecting the side rails 252 and 254. The slider bed 260 is preferably disposed below at least a portion of the upper run 233 a of the conveyor belt 232 to underlie and support the upper run 233 a.

The chassis 224 is preferably unitarily and integrally formed. More particularly, the slider bed 260 and the side rails 252 and 254 are preferably formed unitarily and integrally with each other by means of a stamping process. That is, the slider bed 260 and the side rails 252 and 254 are preferably formed by a single piece of material, most preferably via a stamping process. It is permissible according to some aspects of the present invention, however, for the chassis to be formed by an alternative process or processes and/or to be non-integrally or non-unitarily constructed.

Most preferably, the chassis 224 comprises steel. Even more preferably, the chassis 224 comprises thin gauge steel. For instance, in a preferred embodiment of the present invention, steel having a gauge between ten (10) gauge and twenty (20) gauge is used. More preferably, steel having a gauge between twelve (12) gauge and sixteen (16) gauge is used. Most preferably, fourteen (14) gauge steel is used. However, alternative materials (including but not limited to metals such as aluminum) and/or thinner or thicker gauges fall within the scope of some aspects of the present invention.

Power Module

The power module 226 preferably provides power to the drive roller assembly 234 and more particularly, the drive roller body 238.

The power module 226 most preferably includes a power assembly in the form of a motor assembly 262. The power module 226 further preferably includes a bearing assembly 264 and one or more sensors 266.

In a preferred embodiment, the motor assembly 262 includes a motor 268 and a motor housing 270. The motor 268 is preferably an electric motor, although other motor types fall within the scope of some aspects of the present invention.

Most preferably, the motor 268 includes a stator 272 and a rotor 274. The rotor 274 is rotatable about a motor (or rotor) axis. The motor axis preferably extends laterally (i.e. perpendicularly to the longitudinal axis of the conveyor assembly 212 in a broad sense), although other axis orientations fall within the scope of certain aspects of the present invention. In the illustrated embodiment, the motor axis is coincident with the drive roller axis. That is, in a preferred embodiment, the rotor 274 and drive roller body 238 share a rotational axis.

The stator 272 preferably at least substantially circumscribes the rotor 274, such that the motor 268 is an inner rotor motor. Outer rotor motors or dual rotor motors fall within the scope of some aspects of the present invention, however.

The stator 272 preferably includes a stator core 276 and a plurality of electrically conductive coils 278 wound about the stator core 276.

Preferably, the rotor 274 includes a rotor body 280 and a rotatable output shaft 282 (which may also be referred to as a motor or rotor shaft 282). The rotor body 280 preferably comprises a rotor core 284 and a plurality of rotor magnets 286 arranged arcuately about the rotor core 284. The rotor magnets 286 preferably cooperate with the stator 272 (more specifically, the coils 278 thereof) to impart rotation to the rotor 274.

The rotor body 280 preferably defines axially spaced apart inner and outer rotor body margins 280 a and 280 b, respectively. As will be discussed in greater detail below, the output shaft 282 preferably projects axially from the rotor body 280 beyond the inner rotor body margin 280 a but does not extend beyond the outer rotor body margin 280 b. Rather, a controller 288 (e.g., a printed circuit board, as illustrated) is preferably mounted laterally outward of and immediately adjacent the outer rotor body margin 280 b.

The bearing assembly 264 preferably includes a first bearing 290, a second bearing 294, and a bearing housing 294 in which the bearings 290 and 292 are seated. The bearings 290 and 292 are most preferably components of a unit bearing, as illustrated. However, a variety of bearing configurations fall within the scope of some aspects of the present invention.

Preferably the bearings 290 and 292 and, even more preferably, the entire bearing assembly 264, is disposed laterally inward of the inner rotor body margin 280 a. More particularly, the rotor shaft 282 includes a bearing portion 296. The bearings 290 and 292 engage the bearing portion 296 and rotatably support the rotor 274. The motor 268 can thus be described as cantilevered (with the rotor core 284 and magnets 286 being located on a cantilevered portion of the shaft 282—i.e., these rotor components are not located between a pair of bearings).

The motor housing 270 preferably in part defines a motor chamber 298 in which the motor 268 is at least substantially disposed. In the illustrated embodiment, for instance, the housing 270 includes a cylindrical shell 300 that circumscribes the stator 272, the rotor core 284, the magnets 286, and a portion of the output shaft 282. The insert 244 preferably defines a laterally outer end of the motor chamber 298, while the intermediate insert 246 preferably defines an inner end of the motor chamber. The bearing housing 294 also preferably in part constitutes the motor housing 270 via a flange 302 disposed between the shell and the intermediate insert 246.

The output shaft 282 preferably includes a keyed end 304 disposed at least in part laterally inward of the bearing assembly 264. That is, the keyed end 304 is laterally inward of the bearing portion 296. The keyed end 304 is preferably received within the intermediate insert 246 so as to rotatably drive the intermediate insert 246. The intermediate insert 246 in turn drives rotation of the drive roller body 238 in a broad sense.

In a preferred embodiment, the controller 288 includes the aforementioned sensors 266. The sensors 266 are preferably operably connected to the controller 288 and each positioned near and slightly radially outward of the rotor magnets 286. The sensors 266 are preferably configured to detect a magnetic field and, more particularly, to detect the rotor magnets 286. Most preferably, the sensors 266 are Hall effect sensors.

It is particularly noted that provision of a unit bearing assembly 264 disposed on a single axial side of the stator 272 and the rotor body 280, in contrast to one or more bearings being disposed on each side of the stator and the rotor body, facilitates convenient positioning of the controller 288 and the sensors 266 thereof in near proximity to the rotor body 280. This positioning in turn enables the use of the rotor magnets 286 as the sensed elements for the sensors 266. Provision of a separate magnetic ring or other sensed element(s) is unnecessary. Alternatively stated, the same rotor magnets 286 are used both as sensor pickups or sensed elements and to power the motor 268.

Stiffening Assembly

As noted previously, the chassis 224 preferably includes a stiffening assembly 228. The stiffening assembly 228 comprises a bracket 308 and an insert 310. The insert 310 is preferably discrete from the bracket 308 but, as will be discussed in detail below, disposed thereon. The bracket 308 extends between and interconnects the side rails 252 and 254 and is most preferably disposed at least substantially equidistantly between the fore and aft ends 252 a and 252 b of the side rail 252 and the fore and aft ends 254 a and 254 b of the side rail 254. The bracket 308 also preferably extends perpendicularly to each of the side rails 252 and 254. However, offset positioning and/or non-perpendicular extension falls within the scope of some aspects of the present invention.

Most preferably, each side rail 252 and 254 defines a respective laterally inwardly extending lip 312 or 314. The lips 312 and 314 cooperatively support the bracket 308. More particularly, in the illustrated embodiment, the bracket 308 is bolted to the underside of the lips 312 and 314. Other mounting methods fall within the scope of some aspects of the present invention, however. For instance, screws, latches, adhesives, welds and/or other means of securement might be additionally or alternatively used.

The bracket 308 preferably includes a base 316 and a pair of sidewalls 318 and 320. The base 316 is spaced vertically below and extends planarly parallel to the to the slider bed 260 such that a vertical gap 322 is formed between the slider bed 260 and the bracket 308. The bracket 308 also preferably includes a pair of sidewalls 318 and 320 extending upwardly from the base 316 toward (but not in contact with) the slider bed 260. The sidewalls 318 and 320 might be alternatively configured or omitted in some embodiments of the present invention, however.

The bracket 308 preferably comprises aluminum, although one or more other materials might alternatively or additionally be used. Ideally, any material used for the bracket should be substantially strong and rigid while also being substantially light weight.

A plurality of perforations or openings 324 are preferably formed in the base 316, although the base might alternatively be devoid of openings therethrough. Such perforations 324 aid in weight reduction without substantial losses in strength or rigidity.

The insert 310 is disposed on the bracket 308 and extends upward across at least a portion of the gap 322. Most preferably, the insert 310 fills the entirety or almost the entirety of the vertical dimension of the gap 322 so as to contact or nearly contact the slider bed 260 when no vertically downward load is applied to the slider bed 260 (e.g., when no package 220 or similar is supported thereon). For instance, the insert 310 preferably fills at least seventy-five percent (75%) of the vertical dimension of the gap 322, more preferably at least ninety percent (90%) of the vertical dimension of the gap 322, and most preferably at least ninety-five percent (95%) of the vertical dimension of the gap 322 when the conveyor module 222 is not loaded.

The insert 310 preferably includes lateral sides 310 a and 310 b and fore and aft sides 310 c and 310 d, respectively. In a preferred embodiment, the bracket 308 defines a pair of laterally spaced apart lips 326 and 328 disposed adjacent respective ones of the lateral sides 310 a and 310 b. Most preferably, the lips 326 and 328 abut the lateral sides 310 a and 310 b and aid in securement of the insert 310 relative to the bracket 308. In contrast, the fore and aft sides 310 c and 310 d are preferably spaced from the sidewalls 318 and 320, although contact is permissible according to some aspects of the present invention. Additional securement of the insert 310 to the bracket 308 is most preferably not necessary, although other means, including but not limited to adhesives, latches, fasteners, etc. might additionally or alternatively be used without departing from the scope of some aspects of the present invention.

Preferably, the insert 310 comprises foam. The foam is most preferably a closed cell foam. Most preferably, the foam is a high density closed cell foam such as six (6) lb/ft³ polyethylene foam. Certain variations in density, type of closed cell foam (e.g., an elastomeric foam rather than a polyethylene foam), or type of foam in a broad sense (e.g., open cell foam rather than closed cell foam) fall within the scope of some aspects of the present invention. Most preferably, however, a selected foam will provide sufficient cushioning and support; have a relatively low weight; resist dirt and moisture accumulation and absorption; be substantially tough, resilient, and puncture resistant; have an advantageous thermal insulating capacity and maintain or at least substantially maintain such capacity when subject to expected compressive forces; and be sufficiently low cost.

The bracket 308 and the insert 310 cooperatively stiffen the chassis 224 and, most preferably, resist undesirable bending, flexing, and/or other forms of deflection of the slider bed 260 as a result of vertically downward loading thereof (e.g., due to large packages 220 being disposed on the conveyor belt 232). This stiffening effect is achieved without excessive increases to the overall weight of the conveyor module 222 and in such as manner as to reduce or at least not increase operational noise. In summary, it is preferred in a broad sense that the conveyor module 222 be lightweight yet sufficiently rigid to support substantial packages 220 without excessive distortion, be economical to produce (e.g., terms of material costs, labor, etc.), and operate quietly. The present conveyor module 222 achieves these objectives through an economical and lightweight thin gauge chassis in combination with a lightweight, easy to produce, and easy to assemble stiffening assembly. A thickened chassis, one or more supplemental roller assemblies, and other conventional modifications are avoided.

Tensioning System

As noted previously, the conveyor system 210 preferably includes a tensioning system 230. More particularly, the tensioning system 230 includes a pair of tensioning devices 330 and 332 each coupled to the passive roller assembly 236 and selectively shiftably mounted to the chassis 224 such that shifting of the tensioning system 230 (and, more particularly, each of the tensioning devices 330 and 332) in the fore-aft direction along the chassis 224 results in corresponding fore-aft shifting of the passive roller body 240 relative to the drive roller body 238. The tensioning system 230 thus facilitates adjustment of the tension in the conveyor belt 232.

As will be discussed in greater detail below, each tensioning device 330 and 332 preferably includes a respective sliding bracket 334 or 336 shiftably mounted to the chassis 224. More particularly, each sliding bracket 334 or 336 is preferably mounted to a respective one of the side rails 252 and 254.

Each bracket 334 and 336 preferably includes a plate-like body 338 or 340, respectively, although other forms fall within the scope of some aspects of the present invention. The body 338 preferably defines threaded fore and aft fastener-receiving openings 338 a and 338 b, respectively, as well as a roller shaft opening (not shown). Similarly, the body 340 preferably defines threaded fore and aft fastener-receiving openings 340 a and 340 b, respectively, as well as a roller shaft opening 340 c.

Each side rail 252 and 254 and, more particularly, each respective sidewall 256 or 258 thereof, preferably defines a respective positioning slot 256 a or 258 a extending in the fore-aft direction. The sidewall 256 defines a fore-aft extending roller shaft slot 256 b. Likewise, the sidewall 258 defines a roller shaft slot 258 b, also extending in the fore-aft direction.

Each tensioning device 330 and 332 further preferably includes a respective positioning fastener assembly 342 or 344, each including a pair of positioning fasteners 346.

As best shown in FIG. 16, each positioning fastener 346 is most preferably in the form of a threaded bolt, including a positioning head 346 a and a threaded positioning shaft 346 b. The positioning heads 346 a are preferably at least in part cross-sectionally larger than the corresponding positioning shafts 346 b, for reasons that will be discussed in greater detail below. Most preferably, the shafts 346 b are generally cylindrical to present a shaft diameter. The heads 346 a are preferably frustoconical to present a maximum head diameter adjacent the corresponding shafts 346 b.

The positioning slots 256 a and 258 a preferably have heights corresponding to the diameters of the positioning shafts 346 b such that vertical shifting of the positioning shafts 346 b within the positioning slots 256 a and 258 a is at least substantially prohibited.

Each positioning head 346 a preferably presents a tool-receiving recess 350 configured to receive a hex key (as illustrated), screw driver, or other tool used to rotate the positioning fastener 346.

The positioning shafts 346 b of each pair of positioning fasteners 346 are configured to extend through the positioning slot 256 a and 258 a in the corresponding side rail 252 or 254 and threadably into respective ones of the fastener-receiving openings 338 a, 338 b, 340 a, and 340 b of the bracket bodies 338 and 340. As is conventional for such threaded engagement, rotation of the positioning shafts 346 b results in lateral shifting thereof through the corresponding fastener-receiving openings 338 a, 338 b, 340 a, and 340 b such that each heads 346 a moves laterally nearer to or farther from the corresponding sliding bracket 334 or 336.

More particularly, each head 346 a presents a mating surface 352 extending perpendicularly relative to the corresponding side rail 252 or 254. Each sidewall 256 and 258 presents an inner face 256 c or 258 c, respectively, and an outer face 256 d or 258 d, respectively. Each sliding bracket 334 or 336 presents an inner face 334 a or 336 a, respectively, and an outer face 334 b or 336 b, respectively. Rotation of the positioning fasteners 346 of a given pair in a “tightening direction” (conventionally but not necessarily clockwise) when the threads of the positioning shafts 346 b are engaged with those of the corresponding fastener-receiving openings 338 a, 338 b, 340 a, and 340 b results in lateral shifting of the mating surfaces 352 toward the corresponding outer faces 334 b and 336 b of the sliding brackets 334 and 336 until (1) the mating surfaces 352 of the heads 346 a engage the outer faces 256 d and 258 d of the corresponding sidewalls 256 and 258, respectively, of the side rails 252 and 254 and (2) the outer faces 334 b and 336 b of the sliding brackets 334 and 336, respectively, engage the corresponding inner faces 256 c and 258 c of the sidewalls 256 and 258, respectively, of the side rails 252 and 254. That is, the side rail 252 is squeezed between the corresponding heads 346 a and the sliding bracket 334. The side rail 254 is squeezed between the corresponding head 346 a and the sliding bracket 336. In this secured or fixed state of the tensioning system 230, fore-aft shifting of the positioning fasteners 346 in the corresponding positioning slots 256 a and 258 a and, in turn, fore-aft shifting of the sliding brackets 334 and 336 relative to the corresponding side rails 252 and 254, is restricted or at least substantially prohibited.

In contrast, rotation of the positioning fasteners 346 of a given pair in a “loosening direction” (conventionally but not necessarily counterclockwise) when the threads of the positioning shafts 346 b are engaged with those of the corresponding fastener-receiving openings 338 a, 338 b, 340 a, and 340 b results in lateral shifting of the mating surfaces 352 away from the corresponding outer faces 334 b and 336 b of the sliding brackets 334 and 336 to disengage and/or further shift the mating surfaces 352 of the heads 346 a away from the outer faces 256 d and 258 d of the corresponding side rails 252 and 254, respectively. Any compression of the side rails 252 and 254 between the heads 346 a and the sliding brackets 334 and 336, respectively, is thus decreased or eliminated. Sufficient decrease or elimination of compressive forces, such that the tensioning system 230 is in a shiftable state, facilities at least substantially unrestricted fore-aft shifting of the positioning fasteners 346 in the corresponding positioning slots 256 a and 258 a and, in turn, at least substantially unrestricted fore-aft shifting of the sliding brackets 334 and 336 relative to the corresponding side rails 252 and 254.

Alternatively stated, shifting of each sliding bracket 334 or 336 relative to the corresponding side rail 252 or 254 adjusts the position of the fastener-receiving openings 338 a,338 b and 340 a,340 b relative to the corresponding positioning slot 256 a or 258 b.

Stated yet another way, the positioning fastener assemblies 342 and 344 are operable to selectively secure the respective brackets 334 and 336 to the respective side rails 252 and 254.

In a preferred embodiment, each of the positioning fasteners 346 is coated with an anti-loosening material such as a nylon thread locker patch. This coating restricts inadvertent loosening of the positioning fasteners 346 due to, for instance, vibration. It is noted that, at least in part due to such coating, provision of nuts, lock washers, or other auxiliary pieces to secure the positioning fasteners is unnecessary, further contributing to the advantageous simplicity of the present invention.

As noted previously, each sliding bracket 334 or 336 includes a respective one of the roller shaft openings (e.g., the roller shaft opening 340 c of the bracket 336, with the corresponding roller shaft opening of the bracket 334 not being illustrated herein). Each sidewall 256 and 258 includes a respective one of the roller shaft slots 256 b and 258 b. The passive roller assembly 236 preferably includes roller shafts 354 and 356 extending laterally outwardly from corresponding ones of the inserts 248 and 250. Each roller shaft 354 and 356 extends through a corresponding one of the roller shaft openings (such as the opening 340 c) to restrict fore-aft shifting of the passive roller assembly 236 relative to the sliding brackets 334 and 336. Furthermore, as will be discussed in greater detail below, the roller shafts 354 and 356 extend through corresponding ones of the roller shaft slots 256 b and 258 b so as to be selectively shiftable therein in the fore-aft direction.

More particularly, in a preferred embodiment and as illustrated, the roller shafts 354 and 356 are hexagonal in cross-section. The roller shaft openings (such as the roller shaft opening 340 c of the bracket 336) are likewise hexagonal and sized and shaped to facilitate a close or tight fit about the roller shafts 354 and 356. Most preferably, reliefs 358 are provided at the corners of the openings (such as opening 340 c) to facilitate proper fit. The roller shaft slots 256 b and 258 b preferably have heights corresponding to those of the corresponding roller shafts 354 and 356 such that vertical shifting of the roller shafts 354 and 356 within the roller shaft slots 256 b and 258 b is at least substantially prohibited.

As will be discussed in greater detail below, each roller shaft 354 and 356 includes an adjustment end 354 a or 356 a, respectively, projecting laterally outward beyond the corresponding side rail 252 or 254.

In view of the above, it will be apparent to those of ordinary skill in the art that the present invention facilitates efficient and secure adjustment of the tension of the conveyor belt 232. In a preferred method, for instance, the positioning fasteners 346 are initially loosened to enable sliding of the sliding brackets 334 and 336 relative to the side rails 252 and 254. An operator then grips at least one of the adjustment ends 354 a or 356 a (e.g., using a wrench) and shifts the passive roller assembly 236 in a fore or aft direction relative to the drive roller assembly 234 to, in turn, increase or decrease the tension of the conveyor belt 232 until the desired tension is achieved. (As discussed above, fore-aft shifting of the passive roller assembly 236 is accompanied by fore-aft shifting of the sliding brackets 334 and 336, which slide relative to the corresponding ones of the side rails 252 and 254.) The positioning fasteners 346 are then tightened such that the side rails 252 and 254 are secured between the corresponding mating surfaces 352 and sliding brackets 334 and 336. Fore-aft slipping of the passive roller assembly 236 is thereby restricted and conveyor belt tension is maintained, except as resulting from stretching of the conveyor belt 232 itself, if applicable. In some methods, for instance, it may be desirable to set the conveyor belt 232 to an over-high tension initially so as to achieve an acceptable tension after relaxation of the belt 232 has occurred.

It is particularly noted that the conveyor belt tension firmly holds the roller shafts 534 and 536 against the corresponding brackets 334 and 336, eliminating the need for any external clamps to hold the brackets 334 and 336.

Although the above described configuration of the tensioning system 230 is preferred, it is noted that a variety of modifications may be made without departing from the scope of some aspects of the present invention. For instance, either or both of the fastener-receiving slot and shaft slot might instead be defined by the sliding bracket. Similarly, either or both of the fastener-receiving openings and the shaft-receiving opening might be formed instead in the corresponding side rails. Alternative shapes of the roller shaft are permissible according to some aspects of the present invention, as are modified forms of the adjustment end thereof. The heads of the positioning fasteners might also be alternatively shaped.

Features of one or more embodiments described above may be used in various combinations with each other and/or may be used independently of one another. For instance, although a single disclosed embodiment may include a preferred combination of features, it is within the scope of certain aspects of the present invention for the embodiment to include only one (1) or less than all of the disclosed features, unless the specification expressly states otherwise or as might be understood by one of ordinary skill in the art. Therefore, embodiments of the present invention are not necessarily limited to the combination(s) of features described above.

The preferred forms of the invention described above are to be used as illustration only and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention.

Although the above description presents features of preferred embodiments of the present invention, other preferred embodiments may also be created in keeping with the principles of the invention. Furthermore, as noted previously, these other preferred embodiments may in some instances be realized through a combination of features compatible for use together despite having been presented independently as part of separate embodiments in the above description.

The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and access the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention set forth in the following claims. 

What is claimed is:
 1. A conveyor assembly for use with a mobile vehicle, said conveyor assembly comprising: a conveyor module including— a first roller assembly including a first roller body rotatable about a first axis, a second roller assembly spaced from the first roller assembly in a fore-aft direction and including a second roller body rotatable about a second axis, and a conveyor belt shiftable in response to rotation of at least one of said first and second roller bodies; a power module providing rotational power to at least one of said first and second roller bodies; a vehicle chassis supporting the conveyor module; and a tensioning system operable to adjust the tension of the conveyor belt, said tensioning system including a tensioning device, said tensioning device coupled to the first roller assembly and selectively shiftably mounted to the chassis such that shifting of the tensioning system in the fore-aft direction along the chassis results in corresponding fore-aft shifting of the first roller body relative to the second roller body, thereby facilitating adjustment of the tension of the conveyor belt.
 2. The conveyor assembly of claim 1, said tensioning device including a sliding bracket selectively shiftably mounted to the chassis, said sliding bracket being mounted to said first roller assembly such that said sliding bracket and said first roller body are immovable relative to each other in the fore-aft direction.
 3. The conveyor assembly of claim 2, said chassis including a side rail extending in the fore-aft direction, said sliding bracket being shiftably mounted to the side rail.
 4. The conveyor assembly of claim 3, said tensioning device including a positioning fastener assembly, a first one of said side rail and said sliding bracket defining a positioning slot extending in the fore-aft direction, and a second one of said side rail and said sliding bracket defining a fastener-receiving opening, with shifting of the sliding bracket relative to the side rail adjusting the position of the fastener-receiving opening relative to the positioning slot, said positioning fastener assembly extending through the positioning slot and the fastener-receiving opening and operable to selectively secure the bracket to the side rail.
 5. The conveyor assembly of claim 4, said positioning fastener assembly including a positioning fastener comprising a positioning head and a threaded positioning shaft, said fastener-receiving opening being a threaded opening, said positioning shaft extending through the positioning slot and into the fastener-receiving opening such that selective rotation of the positioning shaft relative to the fastener-receiving opening enables lateral shifting of the positioning head toward the side rail and the sliding bracket and selective securement of the bracket to the side rail.
 6. The conveyor assembly of claim 4, said sliding bracket defining a roller shaft opening, said first roller assembly including a roller shaft extending through said roller shaft opening to restrict fore-aft shifting of the first roller relative to said sliding bracket, said side rail defining a roller shaft slot extending in the fore-aft direction, said roller shaft further extending through said roller slot and being selectively shiftable therein in a fore-aft direction.
 7. The conveyor assembly of claim 6, said roller shaft including an adjustment end projecting laterally outward of said side rail.
 8. The conveyor assembly of claim 1, said first roller assembly including axially spaced apart first and second roller assembly ends, said tensioning device being coupled to said first roller assembly end, said tensioning system including an additional tensioning device operably coupled to the second roller assembly end and selectively shiftably mounted to the chassis such that shifting of the tensioning system in the fore-aft direction along the chassis results in corresponding fore-aft shifting of the first roller body relative to the second roller body, thereby facilitating adjustment of the tension of the conveyor belt.
 9. The conveyor assembly of claim 1, said power module providing rotational power to the second roller body, said first roller body being a passive roller body.
 10. The conveyor assembly of claim 9, said power module including a stator and a rotor rotatable about a third axis, said rotor including a rotor body and a rotor shaft, said rotor shaft including a bearing portion projecting axially from the rotor body, said rotor body including a plurality of rotor magnets operable to cooperate with the stator to impart rotation to the rotor, said power module further including— a pair of bearings engaging the bearing portion and rotatably supporting the rotor, and a sensor configured to sense said rotor magnets.
 11. The conveyor assembly of claim 1, said chassis including— a pair of side rails each extending in the fore-aft direction, and a slider bed extending between and interconnecting the side rails, said slider bed underlying a portion of the conveyor belt, said conveyor assembly further comprising a stiffening assembly, said stiffening assembly including— a bracket extending between and interconnecting the side rails, said bracket being spaced vertically below the slider bed such that a vertical gap is formed between the slider bed and the bracket, and an insert disposed on said bracket and extending upward across at least a portion of said gap.
 12. A conveyor assembly comprising: a conveyor module including— a first roller assembly including a first roller body rotatable about a first axis, a second roller assembly spaced from the first roller assembly in a fore-aft direction and including second roller body rotatable about a second axis, and a conveyor belt shiftable in response to rotation of at least one of said first and second roller bodies; a chassis including— a pair of side rails each extending in the fore-aft direction, and a slider bed extending between and interconnecting the side rails, said slider bed underlying a portion of the conveyor belt; and a stiffening assembly including— a bracket extending between and interconnecting the side rails, said bracket being spaced vertically below the slider bed such that a vertical gap is formed between the slider bed and the bracket, and an insert disposed on said bracket and extending upward across at least a portion of said gap.
 13. The conveyor assembly of claim 12, said insert being discrete from said bracket and said slider bed.
 14. The conveyor assembly of claim 12, said insert comprising foam.
 15. The conveyor assembly of claim 12, said chassis comprising thin gauge steel.
 16. The conveyor assembly of claim 12, said side rails and said slider bed being unitarily and integrally formed.
 17. The conveyor assembly of claim 16, said side rails and said slider bed being integrally stamped.
 18. The conveyor assembly of claim 12, said bracket comprising aluminum.
 19. The conveyor assembly of claim 12, said gap having a vertical dimension, said insert extending upward across at least 90% of the vertical dimension so as to abut or nearly abut the slider bed.
 20. The conveyor assembly of claim 12, further comprising: a power module providing rotational power to one of said first and second roller bodies, said power module including a stator and a rotor rotatable about a third axis, said rotor including a rotor body and a rotor shaft, said rotor shaft including a bearing portion projecting axially from the rotor body, said rotor body including a plurality of rotor magnets operable to cooperate with the stator to impart rotation to the rotor, said power module further including— a pair of bearings engaging the bearing portion and rotatably supporting the rotor, and a sensor configured to sense said rotor magnets. 